(a) Field of the Invention
The present invention relates to an integrated system for detecting and repairing defects and a controlling method thereof. More specifically, the present invention relates to an integrated system for detecting and repairing defects and its controlling method employed for manufacturing micro electronic devices such as semiconductors or thin film transistor liquid crystal displays (TFT-LCD).
(b) Description of the Related Art
A process for manufacturing a TFT-LCD will be first described.
Referring to FIG. 1 (a), when a transparent non-conductive substrate is metallized and patterned, a gate pattern comprising a gate electrode 110 and gate line (not illustrated) is formed. Referring to FIG. 1 (b), a gate insulation film 120 comprised of SiNx is coated on the gate pattern 110, and an amorphous silicon film 130 and a doped amorphous silicon film 140 are layered and patterned on the gate insulation film 120, and active amorphous silicon layer patterns 130 and 140 are then formed. Referring to FIG. 1 (c), a source electrode 151 and a drain electrode 152 are formed on the patterned film of the doped amorphous silicon layer 140, and a data line (not illustrated) is formed on the gate insulation film 120. Referring to FIG. 1 (d), the doped amorphous silicon layer 140 is etched using the source electrode 151 and a drain electrode 152 as masks. Referring to FIGS. 1 (e) and (f), the protective film 160 comprised of SiNx is formed on the source electrode 151 and a drain electrode 152, and a contact hole C1 of the drain electrode 152 is formed through the protective film 160. A transparent conducting material such as an indium tin oxide (ITO) is then coated around the hole C1 and patterned, and thereby, forming a pixel electrode 170.
FIGS. 2 (a) and (b) are flow charts of a conventional manufacturing process as shown in FIGS. 1 (a) through (f).
In the conventional manufacturing process as shown in FIG. 2 (a), a gate pattern comprising a gate electrode and gate line is formed in Step S2. An automatic optical inspection (AOI) or an open/short test (OST) is performed by an automatic optical inspector or an open/short tester in order to inspect the gate pattern in Step S4.
The automatic optical inspector without directly touching the product irradiates light and transmits the reflected light to a sensor through a lens, and examines the product for defects by detecting differences of the light intensity. In this way, visual defects that cannot be detected by electrical inspections can be detected, solving the process reliability and contamination problems. The automatic optical inspector can detect all visual defects, including minute defects or those that cannot be seen with naked eyes on the glass surface. Examples of such defects include film residues, film strips, particles, glass chips, corrosion, spots, photoresist defects, and mask defects.
Following the formation of the gate pattern, the results of the AOI (or OST), i.e., whether or not the above mentioned defects are present, are stored in an electronic file. (Step S6) The stored data comprises coordinate values of the defect locations, as well as the type of defects detected.
This inspected panel together with the file are then transferred to a repairing process. The file is input to a repairer to be used as repair job data on the defective panel. (Step S7)
If no defect is found on the panel on which the gate pattern has been formed or if a defective panel is completely repaired, the panel is transferred to the next process.
The subsequent process is an active pattern forming process that coats an amorphous silicon layer on the gate electrode. (Step S8) Since this active pattern forming process coats nonmetals, an electrical test is not used and only the AOI can be performed. Therefore, the automatic optical inspector performs a visual inspection (Step S10), and if defects are detected, the panel and an associated data file are transferred to the repairer so that the defects can be repaired (Step S13). If no defects are found or the repair process is completed, the panel and data file are transferred to the next data pattern forming process.
After data pattern forming process that fabricates the source electrode, drain electrode and data line, defects are repeatedly examined by AOI. (Steps S15, S16 and S17). After AOI inspection, if no defect is found or if defects are completely repaired, the panel is transferred to the open/short tester to execute the OST. (Step S8)
When data lines are patterned on a TFT-LCD panel, the open/short tester provides electrical signals to each data line to detect the open or short states of each line. The open or short states of the data lines are determined from the OST results. (Step S20) If open/short states are detected, the open data line number is stored in a file, and the defective panel are transferred to the repair process along with the file.
The repairer then repairs the panel referring to the file containing the open data line number (Step S21). The repaired panel is then transferred to a pixel electrode forming process. However, if no defect is found after an OST, the panel is immediately transferred to the pixel electrode forming process.
After forming a pixel electrode (Step S24), the panel is transferred to the automatic optical inspector and is inspected or repaired in the same manner as described previously. (Steps S24-S27) However, after forming a pixel electrode, an array test is also performed, in addition to AOI.
In an array test, each TFT pixel is tested to determine that there are any electrical defects. The array test is performed in the final TFT fabrication process, where a transparent conducting material layer (such as ITO) is formed. An in process tester (IPT), one of the array testers, optically inspects for electrical defects of pixels. The IPT can assess the electrical characteristics of each TFT pixel before completing the TFT assembly. Therefore, pixel defects and line defects, can be detected at an early stage, enhancing the productivity and reducing the costs. The array tester may detect, for example, pixel defects and open or shorted lines.
After testing arrays (Step S28), when the defects are detected, this information is stored in a file and transferred together with the panel to the repair process.
Once repaired referring to the file in the repairing process (Step S31), all the manufacturing, inspection and repair processes on the TFT panel are completed.
FIG. 3 is a process line flow diagram of a TFT panel handled in the manufacturing process of FIG. 2. FIG. 3 indicates the course through which the TFT panel is transferred when all detectable defects are generated.
As shown in FIG. 3, according to the conventional TFT-LCD repairing system, if the inspection and repairing steps are performed for each process, this inspection and repair process has the drawback of taking an inordinate amount of time.
It is an object of the present invention to provide an integrated system for repair and its controlling method that merges files thathave information on defects and to repair the defects as a batch at one time referring to the merged files at a final manufacturing step after all inspections have been finished.
In one aspect of the present invention, an integrated repair system of micro electronic devices comprises a plurality of inspectors for optically or electrically inspecting panels that have predetermined patterns after finishing each process, and storing the inspected results in files with a predetermined format and a repairer, coupled to a plurality of the inspectors, retrieving the files stored by the inspectors and merging the files and executing repair processes as a batch at one time with reference to the merged files.
The integrated repair system further comprises a file server, coupled to a plurality of the inspectors through a network, for storing the files of the inspectors and providing the file when requested by the repairer, an automatic transfer device controlled by a host for automatically transferring the panels between a plurality of the inspectors and between the inspectors and the repairer and an automatic transfer device controller coupled to the host and receiving commands from the host and controlling transfers of the automatic transfer device.
The panels processed by this invention can be thin film transistor (TFT) panels.
The files include data on the coordinates of defects indicating the location of the defects on the panels; defect codes indicating the contents of the defects of the panels; and cell grades indicating the status of the defects on the panels.
The defect codes and the cell grades are merged with reference to coordinates of the defects written in files by a plurality of the inspectors, removing the duplicate parts of these files.
According to another aspect of the present invention, in a repair system comprising a plurality of inspectors that optically or electrically inspects panels where predetermined patterns have been formed and for stores results of the inspections in files with a predetermined format, and a repairer that repairs using the results of the inspections, a method for controlling the integrated repair system is provided, comprising the steps of: (a) forming predetermined patterns on the panels in each process; (b) inspecting optically or electrically the patterns formed on the panels after each process, and, storing the inspection results in a plurality of files with a predetermined format when defects are found on the panels; (c) merging the inspection results stored in the files and removing the duplicate parts; and (d) repair the defects on the panels as a group at once.
The above step (b) further comprises the step of inspecting electrically or optically the patterns on the panels, creating a file when the pixels are defective and storing the coordinates of the defects indicating the locations of the pixels, codes of the defects indicating the contents of the defects and the cell grades indicating defective status, and storing this file in a file server or on a hard disk installed in the inspector.
The above step (c) comprises the steps of first collecting the files through the network and determining whether or not each pixel on the panel is repairable from the defect data stored in the files, and then rejecting the pixel when it is not repairable and second determining whether to merge the files, and in case of merging, merging the files with reference to predetermined coordinates and removing duplicate data, and in case of not merging, connecting a predetermined inspector with a repairer. Then, the panel is repaired one by one with reference to the merged files or a file of a specified inspector.
The step (c) further comprises a step in which the data are merged into a file with reference to the coordinates of the defects for each file, and duplicate data are removed.
In other aspect of the present invention, a method for controlling an integrated repair system comprises the steps of (a) forming gate patterns on panels and optically or electrically inspecting the panels, (b) storing defect data associated with this step (a) in a first file, (c) forming active patterns on the panels and optically inspecting the panels, (d) storing defect data associated with this step (c) in a second file, (e) forming data patterns on the panels and optically or electrically inspecting the panels, (f) storing defect data associated with this step (e) in a third file, (g) forming pixel electrodes on the panels and optically or electrically inspecting the panels, (h) storing defect data associated with this step (g) in a fourth file, (i) forming a merged file by merging the first, second, third, and fourth files, and removing duplicate parts from the first, second, third, and fourth files, and (j) repairing the defects as a batch at once referring to the merged file.
In this present invention, automatic optical inspections are performed on the panels.
Additionally, an open/short tester is used to electrically inspect the panels in the above step (e), and an array tester is used to electrically inspect the panels in the above step (g).
The first through fourth files on defects have coordinates, codes, and cell grades of the defects located on the panels.
In other aspect of the present invention, an automatic defect detection system comprises a defect detector that inspects panels on which patterns have been formed by various manufacturing processes, and detects defects on the panels according to inspection results, and stores the defects in a file with a predetermined format, and a file server that receives the file of defects from the defect detector, and stores the defect data of the panels in a file format from the beginning of the execution of the processes up to the immediately prior process.
The automatic defect detection system further comprises a comparator, coupled to the file server, that compares the defect data of the panels collected up to the previous process with the defects of the panels of the current process stored in the file server.
The automatic defect detection system further comprises a panel ID reader reading the ID of the panel and transferring this data to the comparator. The comparator compares whether or not the panel ID read from the panel ID reader is identical to the in process panel ID stored in the file server.
The defect detector outputs the locations where the defects are located on the panel as coordinates of the defects.
The comparator compares whether the IDs of the panels stored in the file server are identical to the ID of a corresponding panel read from the panel ID reader, and if they are identical, compares data on the defects generated up to the immediate prior process with the defects detected by the inspector up to the current process, and then transfers to the file server the defective data of the current process (excluding the data on defects previously identified) and the data on defects generated up to the current process.
The file server stores IDs of the panels in each process, the data on defects up to current process received from the comparator, and the data on defects of the current process.
In other aspect of the present invention, a method for controlling an automatic defect detection system, comprises the steps of: (a) loading a panel after execution of each process; (b) detecting defects of the panel; (c) comparing the defects of the panel with the defect of the panels up to the immediate prior processes; and (d) storing the defect data of the current process and the defect data up to the immediate prior processes.
This method further comprises a step of reading an ID of the panel and comparing this ID with the IDs of the stored panels in the above steps (a) and (b).